| mean low water | <marine biology> The average height of the low waters over a 19-year period. For shorter periods of observations, corrections are applied to eliminate known variations and reduce the result to the equivalent of a mean 19-year value. All low-water heights are included in the average where the type of tide is either semidiurnal or mixed. Only the lower low-water heights are included in the average where the type of tide is diurnal. So determined, mean low water in the latter case is the same as mean lower low water. (09 Oct 1997) |
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| mean manifest vector | A single cardiac vector representing the average of all vector's present during a given time interval. Synonym: mean manifest vector. (05 Mar 2000) |
| mean sea level | <marine biology> A tidal datum: the arithmetic mean of hourly water elevations observed over a specific 19-year cycle. Points on land can be referenced to a mean sea level, in which case the datum assumes zero elevation. (09 Oct 1997) |
| mean temperature | The average atmospheric temperature in any locality for a designated period of time, as a month or a year. (05 Mar 2000) |
| mean vector | A single cardiac vector representing the average of all vector's present during a given time interval. Synonym: mean manifest vector. (05 Mar 2000) |
| regression of the mean | If, for a symmetrical population with a single mode, a measurement, selected because it is extreme, is repeated, on average the second reading will be closer to the mean than the first. (05 Mar 2000) |
| harmonic mean | The mean calculated as the number of values being averaged, divided by the sum of their reciprocals. (05 Mar 2000) |
| hypothetical mean organism | A hypothetical organism whose characters are the means of the positive characters of the organisms which belong to the same taxon as the HMO, as opposed to the calculated mean organism. (05 Mar 2000) |
| hypothetical mean strain | A hypothetical strain that possesses the characteristics of a calculated mean organism. (05 Mar 2000) |
| standard error of the mean | A statistical index of the probability that a given sample mean is representative of the mean of the population from which the sample was drawn. (05 Mar 2000) |
| law of regression to mean | In a population mating at random, the progeny of a parent with an extreme value for a measurable phenotype will tend on average to have values nearer the population mean than in the extreme parent. See: law of regression to mean. Synonym: law of regression to mean. (05 Mar 2000) |
| absorption coefficient | <physics> Measures the degree of wave absorption defined as the fraction of wave energy lost as the wave travels a unit distance. See: absorption. (15 Jan 1998) |
| attenuation coefficient | 1. <radiobiology> Compton: The fractional number of photons removed from a beam of radiation per unit thickness of material through which it is passing as a result of Compton effect interactions. 2. Linear: The fractional number of photons removed from a beam of radiation per unit thickness of material through which it is passing due to all absorption and scattering processes. 3. Pair Production: That fractional decrease in the intensity of a beam of ionising radiation due to pair production in a medium through which it passes. 4. Photoelectric Effect: That fractional decrease in the intensity of a beam of ionising radiation due to photoelectric effect in a medium through which it passes. (16 Dec 1997) |
| biological coefficient | Rarely used term denoting the energy expended by the body at rest. (05 Mar 2000) |
| Bunsen's solubility coefficient | The milliliters of gas STPD dissolved per milliliter of liquid and per atmosphere (760 mm Hg) partial pressure of the gas at any given temperature. (05 Mar 2000) |